Association between metformin prescription and growth rates of abdominal aortic aneurysms

Background

It has been suggested that diabetes medications, such as metformin, may have effects that inhibit abdominal aortic aneurysm (AAA) growth. The aim of this study was to examine the association of diabetes treatments with AAA growth in three patient cohorts.

Methods

AAA growth was studied using ultrasound surveillance in cohort 1, repeated CT in cohort 2 and more detailed repeat CT in cohort 3. Growth was estimated by the mean annual increase in maximum AAA diameter.

Results

A total of 1697 patients with an AAA were studied, of whom 118, 39 and 16 patients were prescribed metformin for the treatment of diabetes in cohorts 1, 2 and 3 respectively. Prescription of metformin was associated with a reduced likelihood of median or greater AAA growth in all three cohorts (cohort 1: adjusted odds ratio (OR) 0·59, 95 per cent c.i. 0·39 to 0·87, P = 0·008; cohort 2: adjusted OR 0·38, 0·18 to 0·80, P = 0·011; cohort 3: adjusted OR 0·13, 0·03 to 0·61, P = 0·010). No other diabetes treatment was significantly associated with AAA growth in any cohort.

Conclusion

These findings suggest a potential role for metformin in limiting AAA growth.

Optimizing the assessment of quality of life after laryngeal cancer treatment

Reports of the impact of larynx cancer treatment modality on quality of life are conflicting, in part due to varying study methodology. The aims of this study were to (1) provide preliminary comparisons of quality of life following radiotherapy or combination therapy; (2) evaluate a number of measures of quality of life and thereby (3) inform future prospective studies. Thirty-six laryngeal cancer patients, 24 following radiotherapy, 12 following radiotherapy and laryngectomy completed the Functional Assessment of Cancer Therapy (FACT) - General/Head and Neck subscale; Nottingham Health Profile (NHP); and the Hospital Anxiety and Depression scale (HAD), three to 12 months post-treatment. Results showed trends towards a less good quality of life in the combined therapy group over a wide range of outcomes, significant for the disease specific FACT head and neck subscale, NHP emotion (p = 0.04) and isolation (p = 0.027). To the authors' knowledge, however, this is the first demonstration of greater impact of laryngeal cancer on quality of life in younger subjects, who had lower scores among others on emotional wellbeing (p = 0.015) and anxiety (p = 0.035). Younger patients thus appear more likely to need more intensive support through treatment. Many of the physical and psychosocial domains derived from the three tools used were highly correlated. In other words, given the known high morbidity of the disease and its treatment, the selection of tools for head and neck quality of life assessment may be much less important than their universal application.

Fibrinogen Mannheim II: a novel gamma307 His-->Tyr substitution in the gammaD domain causes hypofibrinogenemia

BACKGROUND

In recent years it has become clear that the molecular investigation of hypofibrinogenemia provides unique insight into regions of the fibrinogen molecule that are important in molecular assembly, secretion and stability.

OBJECTIVES

To investigate a case of hypofibrinogenemia at the molecular level.

PATIENTS AND METHODS

The study was conducted on a 37-year-old woman from Mannheim, Germany, who had an antigenic plasma fibrinogen concentration of 0.86 g L(-1). Mutation screening was performed by DNA sequencing and the effect of the identified mutation was investigated at the protein level.

RESULTS

Analysis of exon 8 of the fibrinogen gamma gene identified a heterozygous CAT-->TAT transition at codon 307. This novel His-->Tyr substitution was not detected when plasma fibrinogen was analyzed by electrospray ionization mass spectrometry. The mutation predicts a mass increase of 26 Da in the gamma chain, but purified gamma chains had a normal mass, indicating non-expression of the gamma(Tyr307) chain in plasma fibrinogen.

CONCLUSIONS

This work reports a novel gamma307 His-->Tyr mutation (fibrinogen Mannheim II) that causes hypofibrinogenemia. Crystal structures show that His307 is located immediately adjacent to three residues that have been implicated in fibrin polymerization at the D:D interface. However, the histidine residue appears critical in maintaining structure of the fibrinogen gammaD domain, rather than in determining function.